Hematopoietic consequences of gain-of-function SAMD9 and SAMD9L mutations

功能获得性 SAMD9 和 SAMD9L 突变的造血后果

• 批准号: 10363681
• 负责人: Jason Ross Schwartz
• 金额: $ 14.87万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-11-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10363681
• 关键词: ANXA5 gene; Addison' s disease; Advisory Committees; Alleles; Apoptosis; Architecture; Ataxia; Autophagocytosis; Award; Biological Models; Bone Marrow Diseases; CD34 gene; CRISPR/Cas technology; Caspase; Cell Count; Cell Cycle Arrest; Cell Line; Cell Proliferation; Cell Separation; Cells; Cellular Assay; Childhood; Chromosome 7; Chromosome Deletion; Chromosomes; Clinical; Clonal Evolution; Data; Development; Development Plans; Diagnosis; Disease; Dysmyelopoietic Syndromes; Educational workshop; Ensure; Evolution; Faculty; Flow Cytometry; Genes; Genetic; Genital; Genitalia; Genome engineering; Genomics; Germ-Line Mutation; Goals; Growth; Hematologic Neoplasms; Hematopoietic; Hematopoietic stem cells; Hypocellular Bone Marrow; In Vitro; Infection; Institution; Interferon-alpha; Interferons; K-Series Research Career Programs; Lead; Lesion; Location; Malignant Neoplasms; Maps; Mentors; Modeling; Molecular; Monosomy 7; Mutate; Mutation; Myelogenous; Myeloid Cells; Myelopoiesis; Myeloproliferative disease; Neoplasms; Nucleotides; Outcome; Output; Pancytopenia; Pathogenesis; Pathologic; Pathway interactions; Patients; Pediatric Hematology; Phenotype; Physicians; Prognosis; Proteins; Publishing; Recovery; Reporting; Research; Research Support; Resolution; Resource Sharing; Saint Jude Children' s Research Hospital; Sampling; Scientist; Series; Somatic Mutation; Stains; Syndrome; Time; Uniparental Disomy; Variant; alanine aminopeptidase; career; career development; chromosome 7 loss; clinical phenotype; cohort; cytotoxic; differential expression; experience; gain of function; gain of function mutation; genome sequencing; hematopoietic cell transplantation; improved; in vivo; induced pluripotent stem cell; insight; lectures; mutant; pediatric myelodysplastic syndrome; pressure; repaired; senescence; skills; stem cell model; stem cells; success; tool; transcriptome sequencing

PROJECT SUMMARY Heterozygous germline mutations in SAMD9 and SAMD9L have recently been described as a new class of MDS predisposing lesions and are present in approximately 10-20% of pediatric MDS cases. We and others have shown in published reports that MDS-associated germline mutations in SAMD9/9L increase the antiproliferative activity of the encoded protein and lead to hypocellular bone marrow with decreased myeloid cell numbers. In addition, we have shown that the development of a myeloid disease is associated with partial or full loss of chromosome 7 that results from the non-random loss of the pathologic mutation. Interestingly, somatic revertant mutations including in cis single nucleotide changes and conversion of the mutant allele to the wild-type through uniparental disomy occur in some cases which leads to hematopoietic recovery. Remarkably, some patients with monosomy 7, leading to a presumptive diagnosis of MDS, also achieve hematopoietic recovery through spontaneous disappearance of the monosomy 7 clone. These data lead to the hypothesis that gain-of- function (GoF) SAMD9/9L proteins are cytotoxic and cause strong selective pressure for cells lacking the mutant allele. The molecular mechanisms through which SAMD9/9L GoF mutations inhibit myelopoiesis, and the spectrum of secondary mutations leading to either MDS, MDS/AML (e.g. SETBP1), or spontaneous recovery is unknown. The proposed studies will investigate these questions through two specific aims: 1.) to determine the molecular and functional impact of mutant SAMD9 and SAMD9L expression during myeloid differentiation using and iPSC model system of pediatric MDS, and 2.) to determine the clonal architecture of cells expressing mutant SAMD9 and SAMD9L using serial patient samples and single cell genomics. A Mentored Clinical Scientist Research Career Development Award (K08) will provide the candidate with the amount of protected time needed to achieve his career goal of independence as a physician scientist and focus on improving the clinical outcomes of pediatric MDS patients through understanding the mechanisms of their disease pathogenesis. A strong career development plan including an experienced and successful faculty advisory committee, clear plans for progress assessments, and attendance at numerous courses, lectures, and workshops to increase proficiency in technical and management skills will accompany these research goals to ensure success as an independent physician scientist. This award will be completed at St. Jude Children’s Research Hospital (St. Jude), one of the world’s leading academic institutions focused on the research and treatment of pediatric catastrophic diseases, making it an exemplary location for an early career physician scientist to develop his career. In addition to the strong institutional support, St. Jude offers unmatched research support with facilities including the Genome Sequencing Facility at the Hartwell Center, a Flow Cytometry and Cell Sorting Shared Resource, and the Center for Advanced Genome Engineering (CAGE).

项目总结 SAMD9和SAMD9L的杂合胚系突变最近被描述为一类新的MDS 易患皮损，约占儿童MDS病例的10%-20%。我们和其他人有 已发表的报告显示，SAMD9/9L中与MDS相关的生殖系突变增加了抗增殖剂 编码蛋白的活性降低，导致骨髓髓系细胞数量减少。在……里面 此外，我们已经证明，髓系疾病的发展与部分或全部失去 7号染色体是由病理性突变的非随机丢失造成的。有趣的是，体细胞突变株 突变，包括顺式单核苷酸变化和突变等位基因向野生型的转化 在某些情况下，会出现单亲二体，这会导致造血恢复。值得注意的是，一些患者 与单体7，导致推定诊断MDS，也实现了造血恢复通过 单体7克隆的自发消失。这些数据导致了这样的假设，即收益- 功能(GoF)SAMD9/9L蛋白具有细胞毒性，对缺乏的细胞有很强的选择压力 突变的等位基因。SAMD9/9L Gof突变抑制骨髓生成的分子机制 以及导致MDS、MDS/AML(例如SETBP1)或自发的继发性突变的谱 恢复情况尚不明朗。拟议的研究将通过两个具体目标来调查这些问题：1)至 确定突变的SAMD9和SAMD9L在髓系中的表达对分子和功能的影响 儿科MDS的辨证应用和IPSC模型体系；确定克隆体系结构的步骤 使用连续患者样本和单细胞基因组学研究表达突变SAMD9和SAMD9L的细胞。 指导临床科学家研究职业发展奖(K08)将为候选人提供 作为一名内科医生、科学家和专注者，实现独立的职业目标所需的保护时间 通过了解MDS的发病机制改善儿童MDS的临床结局 疾病发病机制。强大的职业发展计划，包括经验丰富且成功的教职员工 咨询委员会，进度评估的明确计划，以及参加许多课程、讲座和 提高技术和管理技能熟练程度的研讨会将伴随着这些研究目标 确保作为一名独立的内科科学家取得成功。该奖项将在圣犹大儿童会完成 研究医院(圣犹大)，世界领先的学术机构之一，专注于研究和 治疗儿科灾难性疾病，使其成为早期职业医生的模范地点 科学家来发展他的事业。除了强大的机构支持外，圣裘德大学还提供了无与伦比的研究 支持的设施包括哈特维尔中心的基因组测序设施，流式细胞仪和 细胞分类共享资源和高级基因组工程中心(CAGE)。